Electric switch



Jul 'zz 1924.

G. A; BURNHAM ELECTRIC SWITCH Filed Oct. 19. 1920 2 Sheets-Sheet. l

July 22 1924. I 1,502,640

G. A. BURNHAM ELECTRIC SWITCH Filed Oct. 19 1920 2 Sheets-Sheet 2 3 5: I KW Patented July 22, 1924..

UNITED STATES v PATENT OFFICE.

GEORGE A. BUENHAM, OF SAUGUS, MASSACHUSETTS, ASSIGNOR, BY MESNE ASSIGN- .MENTS, TO CONDIT ELECTRICAL MANUFAGTUR-ING COMPANY, A GORPORA'IION OF MASSACHUSETTS.

ELECTRIC SWITCH.

Application filed October 19, 1920. Serial No, 417,902.

T 0 all whom it may concern:

' Be it known that I, GEORGE A. BURN- HAM, a citizen of the United States, residing at Saugus, in the county of Essex and State .of Massachusetts, have invented an Improvement in Electric Switches, of which the following is a specification.

This invention relates to oil-immersed electric switches and has for its object generally to improve the construction and operation, and, specifically, to improve the current carrying and current interrupting properties of the switch.

In carrying out my invention, I provide an improved oil receptacle which is formed with a reduced neck-portion adapted to be received within the depending flange of the switch frame, and an enlarged body-portion adapted to contain the oil in which the switchmembers are immersed. This construction provides an oil receptacle of increased volume and, as the current interrupting capacity of a switch bears some relation to the volume of the space enclosing the switch'members, the volume of oil in which the switch members are immersed, and the volume of the expansion space above the oil; this construction provides an oil switch having increased current-interrupting capacity. The surface area of the oil receptacle and, consequently, its ability to dissipate heat is also increased, whereby the current-carrying capacity of the switch is increased; and, by virtue of the increased cooling effect, the circuit interrupting capacity of the switch is further increased.

A further object of this invention is to provide the oil receptacle as an attachment to be applied to existing switches.

The oil receptacle herein disclosed is in some respects similar to the oil receptacle disclosed in my co-pending application Serial No. 354,920, filed January 29, 1920.

Fig. 1 is a side elevation of a multi-phase switching unit embodying my invention.

Fig. 2 is a side elevation, partly in section, of a single phase switch embodying my invention.

Fig. 3 is a transverse section along line 33 of Fig. 2.

Fig. 4 is a plan view of the switch frame of the switch of Figs. 2 and 3, the switch members and operating mechanism being re moved.

Fig. 5 is a transverse section, similar to Fig.3, of amodified form of switch.

Fig. 6 illustrates the oil receptacle embodying my invention as an attachment to be applied to existing switches.

As here shown, the switch with which my invention is associated includes the switch frame 10 bearing the stationary switch members 11, movable switch members 12 and operating mechanism 13. In Fig. 2 the switch frame is formed with the extended arm 14: by which it may be secured to a support, while in Fig. 1 the switch frame is secured to a back-bone 15 carried by the standards 16.

The switch frame illustrated in Fig. 2 is formed with the depending peripheral flange or apron 17 within which the oil receptacle is adapted to be received and said apron is adapted to extend downwardly along the side wall of the oil receptacle to support it against distortion due to internal gaseous pressure within the switch. The frame is also formed with the plurality of transverse ribs 18 which serve to strengthen it the better to resist the relatively high internal gaseous pressures which may be developed due to circuit interruption. 5 Aperipheral rib 19 also extends horizontally about the switch frame beyond the depending flange also to strengthen the frame.

The oil receptacle embodying my invention has the body-portion 20 which extends beyond the flange or apron 17 and which also may extend beyond the horizontal flange 19 although, in a multi-phase switching equipment it is desirable, by reason of the close spacing of the independent switch units, not to extend the oil receptacle, laterally, beyond said rib, to such a distance as to necessitate increased spacing between the units. Usually, at the ends, there are no restrictions and the oil receptacle may extend any suitable distance beyond said flange.

The side walls of the oil receptacle extend, preferably vertically, upward to a height sufficient to provide a suitable volume for oil and then slope inwardly and upwardly as at 21 and then again extend, preferably, vertically, upward to form the reduced neck portion 22 which is received within the apron 17. Preferably a small clearance space 17 extends peripherally between the neck portion and the apron to provide a downwardly directedyent passagefcr gas and o il from the switch; I a

The oil receptacle is provided with suitable means .by which it is, preferably removably,ilse cured to the-switch frame. Said securing means may comprise the bolts 23 fixed to the inside of the neck and extended through holes 24 in the switch frame and provided with wing nuts 25 removably threaded on the upper ends thereof. An insulating lining 26 is contained within the enlarged body portion 20 of the oil receptacle and extends, preferably, to thesloping portion 21 of-the receptacle. 1

The oil level within the receptacle is pref- .erablyatorabelow the sloping portion 21 and the space A above the surface ofthe oil and under the switch: frame forms an expansion chamber. Due to the enlarged body-portion of the receptacle the volume of thdexpansion chamber is considerably increased over the usual construction wherein the oil recep- ,tacle extends vertically downward from the top, and the interrupting capacity of the switch is thereby increased. Because of the enlarged body pOltion, a considerably greater amount of oil may be contained in V the receptacle than otherwise whereby, also,

the interrr-upting capacity is increased.

lVh le the oil receptacle, llustrated in F 1g. 2, is des gned more particularly for use with pendingapplication Serial No. 309,853, filed July 10, 1919, which application has eventua-ted in Patent No. 1,413,156, datedv April 18, L922, Fig. 5 illustrates an oil receptacle embodying my invention especially adapted for use in connection with a switch frame of more .or less common construction. In the switch frame set forth in Fig. 5, the depending flange or apron 17 is considerably shos e yth n th rr pond ng pr 1 f B g 2 and t-h nec po n 2 o h Oil r ceptacle may be correspondingly shorter in vertical extent. Otherwise, the construction of the oil receptacle may be the same as that name to this specification.

to the bottom of the receptacle, .a switch frame disposed over said reduced neck and comprising a cover for the receptacle,and stationary and movable switch members supported by said cover and depending through said reduced neck into the enlarged body of said receptacle.

2. The combination of supporting means,

a plurality of substantially contiguous switch frames carried by said supporting means, said switch frames having depending peripheral aprons, and a plurality of-substantially contiguous oil receptacles having ,reducedneok portions received within the depending per pheral aprons and'supportecl from said switch frame. a switch frame such as is setfforth in my co v The combination of supporting means, a plural ty of substantially contiguous oil receptacles having reduced neck portions supported and depending from said switch nes carried by said supporting 111821118,

plura ty i switch b rs a ie by Said frames, said receptacles being adapted to' contain .oil in which said switch members depend. 7

' I in testimony whereof, I have signed my .enonen A. BURNHAM. 

